The present invention relates to an industrial robot and a method of operating the industrial robot.
In recent years, the improvement of maintenance has been increasingly demanded with respect to industrial robots.
Generally, a driving motor for industrial robots is equipped with a holding brake for holding the robot position when the power supply is turned off.
The configuration of a conventional robot will be described in the following with reference to FIG. 2.
FIG. 2 shows a configuration of a prior art industrial robot. An industrial robot of conventional type comprises a control device 11, hand control unit 15, manipulator 12, cable 13, and connector 14. The cable 13 connects the manipulator 12 and the control device 11.
By using the hand control unit 15 of the control device 11, the robot can be operated to change its position.
However, when the operator is unable to operate the robot by using the control device 11 as the control device 11 is in alarm mode, the control device 11 is not supplied with power, or the manipulator 12 is not connected to the control device 11, the following two methods have been commonly employed to operate the robot.
One of the methods is such that the cable 13 which connects the manipulator 12 and the control device 11 of the robot is first disconnected, and after that, a voltage for releasing the holding brake is applied to the connector 14 connected to the holding brake, thereby releasing the holding brake. The other method is such that a means (a switch or the like) for releasing the holding brake is operated to release the holding brake. However, in these methods, it is generally required that the manipulator 12 be connected to the control device 11 and also that the control device 11 be supplied with power.
The means (a switch or the like) for releasing the holding brake is installed in the control device 11 or manipulator 12. Manual releasing of a holding brake of such motor is one of the regulation items specified in some of the safety standards.
A method of releasing a holding brake of a driving motor for such prior art industrial robot involves the following problems.
In case the cable 13 which connects the manipulator 12 and the control device 11 of the robot is disconnected, and a voltage for releasing the holding brake is applied to the connector 14 connected to the holding brake, then it is necessary to separately prepare a power supply to generate the voltage for releasing the holding brake.
Further, similarly, in case the cable 13 which connects the manipulator 12 and the control device 11 of the robot is disconnected, and a voltage for releasing the holding brake is applied to the connector 14 connected to the holding brake, then it is necessary to disconnect the cable 13 and also to retrieve the pin number of connector 14 connected to the holding brake. Accordingly, it is not easy to release the holding brake.
Furthermore, when a means (a switch or the like) for releasing the holding brake is operated, it is absolutely required that the control device 11 be supplied with power. That is, in case the control device 11 is not supplied with power just after installation of the robot, and in case the manipulator 12 is not connected to the control device 11, then it is difficult to change the position of the robot.
The present invention provides an industrial robot which can meet the requirement for easier maintenance.
An industrial robot in an embodiment of the present invention comprises:
(a) a robot body;
(b) a manipulator to control the operation of the robot body;
(c) a control device to control the manipulator;
(d) a first path disposed between the manipulator and the control device; and
(e) a second path disposed between a commercial power source and the manipulator.
Preferably, the voltage supplied from the commercial power source in the second path is applied to the manipulator, and then the robot body becomes freely movable without being controlled by the manipulator.
A method of operating an industrial robot of the present invention comprises:
(a) a step of feeding a robot system, wherein the robot system comprises
a robot body,
a manipulator to control the operation of the robot body,
a control device to control the manipulator,
a first path disposed between the manipulator and the control device, and
a second path disposed between a commercial power source and the manipulator;
(b) a step of operating the manipulator by controlling the control device by the first path, thereby controlling the operation of the robot body; and
(c) a step of freely moving the robot body without being controlled by the manipulator, applying a voltage from the commercial power source to the manipulator when it is unable to control the control device by the first path.
With the above configuration, the robot position can be easily changed by applying a voltage from a commercial power source. As a result, an industrial robot which assures easier maintenance may be obtained.